Partly revert `calculate_statistics` change
Partly revert `calculate_statistics` change

`@pairs` is an array of arrays, not a hash.

yalab/rails,iainbeeston/rails,betesh/rails,Stellenticket/rails,rails/rails,lcreid/rails,fabianoleittes/rails,bogdanvlviv/rails,schuetzm/rails,repinel/rails,betesh/rails,repinel/rails,Vasfed/rails,palkan/rails,esparta/rails,BlakeWilliams/rails,palkan/rails,tjschuck/rails,iainbeeston/rails,gauravtiwari/rails,joonyou/rails,jeremy/rails,georgeclaghorn/rails,Vasfed/rails,gauravtiwari/rails,kddeisz/rails,BlakeWilliams/rails,Vasfed/rails,kddeisz/rails,yahonda/rails,yhirano55/rails,eileencodes/rails,kmcphillips/rails,MSP-Greg/rails,repinel/rails,vipulnsward/rails,vipulnsward/rails,rails/rails,kmcphillips/rails,fabianoleittes/rails,prathamesh-sonpatki/rails,yahonda/rails,palkan/rails,jeremy/rails,yhirano55/rails,lcreid/rails,jeremy/rails,tjschuck/rails,yawboakye/rails,Edouard-chin/rails,eileencodes/rails,lcreid/rails,repinel/rails,kddeisz/rails,gauravtiwari/rails,yalab/rails,rafaelfranca/omg-rails,MSP-Greg/rails,Vasfed/rails,BlakeWilliams/rails,tjschuck/rails,mechanicles/rails,EmmaB/rails-1,tgxworld/rails,yahonda/rails,vipulnsward/rails,Erol/rails,Edouard-chin/rails,palkan/rails,betesh/rails,mechanicles/rails,Erol/rails,rails/rails,rafaelfranca/omg-rails,schuetzm/rails,eileencodes/rails,mechanicles/rails,BlakeWilliams/rails,starknx/rails,yawboakye/rails,prathamesh-sonpatki/rails,MSP-Greg/rails,mechanicles/rails,yawboakye/rails,kmcphillips/rails,tjschuck/rails,prathamesh-sonpatki/rails,Envek/rails,prathamesh-sonpatki/rails,starknx/rails,vipulnsward/rails,joonyou/rails,bogdanvlviv/rails,yawboakye/rails,tgxworld/rails,kddeisz/rails,schuetzm/rails,esparta/rails,bogdanvlviv/rails,yahonda/rails,yhirano55/rails,joonyou/rails,jeremy/rails,yhirano55/rails,eileencodes/rails,bogdanvlviv/rails,Erol/rails,rails/rails,georgeclaghorn/rails,Stellenticket/rails,fabianoleittes/rails,fabianoleittes/rails,Stellenticket/rails,Envek/rails,tgxworld/rails,MSP-Greg/rails,Edouard-chin/rails,EmmaB/rails-1,esparta/rails,iainbeeston/rails,lcreid/rails,betesh/rails,esparta/rails,Envek/rails,yalab/rails,georgeclaghorn/rails,tgxworld/rails,Stellenticket/rails,georgeclaghorn/rails,schuetzm/rails,rafaelfranca/omg-rails,iainbeeston/rails,Erol/rails,Envek/rails,starknx/rails,joonyou/rails,kmcphillips/rails,EmmaB/rails-1,yalab/rails,Edouard-chin/rails